1. Field
Exemplary embodiments of the present invention relate to a semiconductor design technology, and more particularly, to a semiconductor device for generating a data reference voltage in the semiconductor device, a semiconductor system including the semiconductor device, and an operating method thereof.
2. Description of the Related Art
In a low-power and high-speed semiconductor device, such as a double data rate type four (DDR4) memory device, a training test of a data reference voltage VREF_DQ that defines a reference voltage level of a data input buffer is performed in the semiconductor device.
To perform the training test, a semiconductor controller provides a 6-bit level training code to the semiconductor device, and the semiconductor device generates the data reference voltage VREF_DQ in the semiconductor device by adjusting the level of the data reference voltage VREF_DQ in response to the 6-bit level training code.
In a conventional semiconductor device, the semiconductor controller generates the data reference voltage VREF_DQ and provides the generated data reference voltage VREF_DQ to the semiconductor device. However, in the configuration described above, the data reference voltage VREF_DQ is generated in the semiconductor device, and as a result, a parameter outside of the semiconductor device is to be sensed so that a result of the training test can be obtained. For example, the result of the training test may be a time taken until the data reference voltage VREF_DQ reaches a target level.
When the parameter is directly sensed, the measured parameter may not be accurate due to capacitive and loading elements of a monitoring pad and sensing equipment.
More specifically, although the parameter is measured using a small unit such as a nanosecond, sensing the parameter not in the semiconductor device is difficult to accurately measure.
Therefore, when the data reference voltage VREF_DQ is not normally generated in the semiconductor device, the data reference voltage VREF_DQ may not be accurately sensed.